(1) Field of the Invention
The present invention relates to an improved resonant radio frequency wave coupler apparatus for creating and maintaining uniform electron cyclotron resonance (ECR) in a low pressure plasma. In particular, the present invention relates to an apparatus where magnetic fields are essentially perpendicular to electric fields of higher modes so as to create and maintain uniform ECR at low pressures and more particularly to an apparatus which creates a plasma with a large processing surface area.
(2) Prior Art
U.S. Pat. No. 4,727,293 to Asmussen, Reinhard and Dahimene describes a resonant radio frequency wave coupler apparatus which creates and maintains ECR. In this apparatus no attempt was made to optimally match the static magnetic and microwave electric fields in any particular manner. The problem was to provide an improved apparatus with more uniform ECR.